Field
This disclosure relates generally to fuses in semiconductor devices, and more specifically, to fuses and resistors using interconnect layers and vias.
Related Art
Fuses are commonly used in semiconductor manufacturing and often require significant space. Blowing the fuses is generally an issue and is commonly done with lasers. One of the issues with fuses is that the fuse must be tested in a separate context from the context in which they are blown. Also the blowing occurs prior to packaging. Thus the process is time consuming and even after the effort of the selective blowing of the fuses, there is a delay time from when the fuse can be tested. Also, the laser may cause the spread of conductive material on top of the integrated circuit which may cause a problem with the operation of the integrated circuit. An alternative is to use electrical circuits onboard the semiconductor chip to perform the blowing. This requires current and the current can be quite large. In a particular situation, the process may be such that the fuse cannot be blown. The fuse must not be so conductive relative to the surrounding conductive material as to result in the heat not being sufficiently focused on the fuse to effectively blow the fuse. Also resistors provide difficulties. Controlling the resistance of a resistor has long been an issue with semiconductor manufacturing. This can especially be true for resistors at the relatively high and relatively low resistance values. For example, for low resistance values, metal is used and long lengths may be used to provide some control by providing some increase in resistance. Height and width are typically dictated by the particular technology being used. Thus providing various increments of resistance can be challenging without using length as the variable, which requires significant space.
Accordingly there is a need to provide a fuse that can be made as part of an integrated circuit that improves upon one or more of the issues raised above.